JP4964903B2 - Elevator equipment - Google Patents

Description

  The present invention relates to an elevator apparatus that operates a car with high efficiency by effectively using the capacity of a drive device.

  In a conventional elevator control device, the speed at the time of traveling at a constant speed and the acceleration / deceleration speed at the time of acceleration / deceleration traveling are changed within the driving range of the motor and the electric equipment that drives the motor according to the load amount of the car. Thereby, the remaining power of a motor is utilized and the operation efficiency of a cage | basket | car is improved (for example, refer patent document 1).

JP 2003-238037 A

  In the conventional elevator control apparatus as described above, it is necessary to consider the processing of regenerative power generated from the motor, but it is not clear how to perform the processing. For this reason, the regenerative voltage exceeds the limit value of the voltage, the expected deceleration cannot be obtained, and there is a possibility that the car goes too far over the stop position.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain an elevator apparatus that can appropriately consume regenerative power while operating a car with high efficiency.

  The elevator apparatus according to the present invention includes a hoisting machine having a driving sheave and a motor for rotating the driving sheave, suspension means wound around the driving sheave, a car suspended by the suspension means and lifted and lowered by the hoisting machine, A power conversion device that controls the power supplied to the motor, and a control device that controls the power conversion device, the control device estimates the maximum value of the regenerative voltage during the regenerative operation of the hoist when the car is running, When the estimated maximum value of the regenerative voltage reaches a predetermined voltage limit value, the power converter is controlled so as to stop the increase of the estimated maximum value of the regenerative voltage.

BRIEF DESCRIPTION OF THE DRAWINGS It is a block diagram which shows the elevator apparatus by Embodiment 1 of this invention. It is a graph which shows an example of the time change of the speed command value in the elevator apparatus of FIG. 1, acceleration, a motor line voltage, a regeneration voltage estimated value, and an acceleration stop command.

Preferred embodiments of the present invention will be described below with reference to the drawings.
Embodiment 1 FIG.
1 is a block diagram showing an elevator apparatus according to Embodiment 1 of the present invention. The car 1 and the counterweight 2 are moved up and down in the hoistway by the hoisting machine 3. The hoisting machine 3 includes a motor 4, a drive sheave 5 that is rotated by the motor 4, and a brake (not shown) that brakes the rotation of the drive sheave 5.

  The motor 4 is provided with a speed detector 6 for detecting the rotational speed of the motor 4 and the magnetic pole position. For example, an encoder or a resolver is used as the speed detector 6.

  A plurality of main ropes 7 (only one is shown in the figure) as suspension means for suspending the car 1 and the counterweight 2 are wound around the drive sheave 5. As the main rope 7, for example, a normal rope or a belt-like rope can be used.

  Electric power from the power source is supplied to the motor 4 via the power converter 8. As the power converter 8, for example, a PMW-controlled inverter that adjusts the output voltage by generating a plurality of DC voltage pulses within the fundamental frequency of the AC voltage is used. In such an inverter, the output voltage to the motor 4 is changed by adjusting the voltage switching duty ratio.

  Further, a circuit breaker (not shown) is provided between the power converter 8 and the power source. Overcurrent to the power converter 8 is prevented by a circuit breaker. The value of the current supplied from the power converter 8 to the motor 4 is detected as a motor current value by a current detector (CT) 9.

  The regenerative resistor 10 consumes the electric power generated by the motor 4 during the regenerative operation of the hoisting machine 3 as heat. In this case, the line voltage applied to the motor 4 is limited by the capacity of the regenerative resistor 10. On the other hand, in an elevator apparatus that does not have the regenerative resistor 10, the power generated by the motor 4 is controlled and returned to the power source by a matrix converter or simple regeneration. In this case, the line voltage applied to the motor 4 is limited by the power supply voltage.

  The power conversion device 8 is controlled by the control device 11. The control device 11 generates a speed command so as to increase the maximum speed and acceleration of the car 1 as much as possible and reduce the traveling time of the car 1 within the allowable range of the drive system equipment. In addition, the control device 11 includes a management control unit 12, a speed command generation unit 13, a movement control unit 14, and a speed limit unit 15. Based on the information from the car operation panel 16 and the landing operation panel 17, the management control unit 12 creates operation management information (for example, information on the destination floor of the car 1 and a travel command) related to the operation of the elevator apparatus.

  The speed command generating unit 13 generates a speed command for the car 1, that is, a speed command for the hoisting machine 3, based on the operation management information from the management control unit 12, and sends this to the movement control unit 14 and the speed limiting unit 15. Output. In addition, the speed command generation unit 13 calculates a virtual speed pattern that starts decreasing acceleration and stops at the destination floor at each time during constant acceleration, and in this speed pattern, decelerates from the current time by a constant speed. The travel distance between the constant acceleration and deceleration that travels until the start is calculated, and this is output to the speed limiter 15.

  The movement control unit 14 controls the movement of the car 1 based on the speed command from the speed command generation unit 13. The movement of the car 1 is performed by controlling the power conversion device 8 of the movement control unit 14. Further, the movement control unit 14 includes a speed controller 18 and a current controller 19.

  The speed controller 18 obtains the difference between the speed command from the speed command generator 13 and the rotational speed information from the speed detector 6 as speed deviation information, and outputs the obtained speed deviation information to the current controller 19. . The current controller 19 obtains a motor current target value based on the speed deviation information from the speed controller 18, and the power conversion device so that the motor current value detected by the current detector 9 matches the motor current target value. 8 is controlled.

  The control command includes a motor current command for adjusting the motor current supplied to the motor 4, a torque current command for adjusting a torque current for generating a rotational torque in the motor 4, and a voltage applied to the motor 4. The voltage command is included. The voltage command includes information on the switching duty ratio of the voltage with respect to the motor 4.

  Further, the current controller 19 obtains a component of the motor current detected by the current detector 9 that causes the motor 4 to generate rotational torque as a torque current, and outputs information on the obtained torque current to the speed limiter 15. . The motor current value, the motor current command value, the torque current value, the torque current command value, the voltage command value, and the switching duty ratio of the voltage with respect to the motor 4 are related to the output of the hoisting machine 3. It is drive information according to the output of the hoisting machine 3 when it is moved.

  The speed limiter 15 estimates by calculation the maximum value of the regenerative voltage that can be generated by the motor 4 during travel when traveling at a certain acceleration time to reduce acceleration from a certain time, and when this reaches the limit value, An acceleration stop command is output to the speed command generator 13. Further, the speed limiter 15 has a voltage estimator 20 and an acceleration stop commander 21.

When the hoisting machine 3 performs the regenerative operation, the acceleration is decreased from the constant speed traveling, and the regenerative voltage becomes maximum at time t ′ when moving to the constant decelerating traveling. The voltage estimator 20 estimates the voltage V _a ′ at the time t ′ from the speed command from the speed command generator 13 and the constant acceleration / deceleration movement distance and the torque current command value from the movement control unit 14. Further, this maximum regenerative voltage estimated value V _a ′ is output to the acceleration stop command device 21.

The acceleration stop command unit 21 compares the maximum regenerative voltage estimated value V _a ′ from the voltage estimator 20 with the voltage limit value, and when V _a ′ reaches the voltage limit value, the acceleration command generation unit 13 accelerates the speed command generation unit 13. Output a stop command. Speed command generating section 13, when increasing the speed command at a constant acceleration, when receiving the information of the acceleration stop command from the acceleration stop command device 21, the speed command of the car 1, the acceleration during the acceleration jerk time t _a Is reduced to 0 and the vehicle moves to a constant speed. That is, the speed command generation unit 13 obtains a speed command for releasing the stop of constant acceleration when the estimated line voltage applied to the motor 4 is lower than the limit value. This prevents the line voltage applied to the motor 4 from becoming higher than the limit value.

Here, the control device 11 includes a computer having an arithmetic processing unit (CPU and the like), a storage unit (ROM, RAM, hard disk and the like), and a signal input / output unit. That is, the function of the control device 11 is realized by a computer. The control device 11 repeatedly performs computation processing for each computation cycle t _s.

  Next, the operation will be described. When call registration is performed by operating at least one of the car operation panel 16 and the hall operation panel 17, call registration information is transmitted to the control device 11. Thereafter, when an activation command is input to the control device 11, power is supplied from the power conversion device 8 to the motor 4, the brake of the hoisting machine 3 is released, and the movement of the car 1 is started. Thereafter, the speed of the car 1 is adjusted by the control of the control device 11 with respect to the power conversion device 8, and the car 1 is moved to the destination floor where the call registration is performed.

  Next, a specific operation of the control device 11 will be described. In the acceleration / stop command device 21, either a constant acceleration enable determination or an acceleration stop command determination is performed based on the estimated line voltage applied to the motor 4. Further, when call registration information is input to the control device 11, operation management information is created by the management control unit 12 based on the information.

  Thereafter, when the determination of the acceleration stop command device 21 is a determination that constant acceleration is possible, the speed command generator 13 obtains a set speed, that is, a speed command, based on the operation management information from the management controller 12. This speed command is calculated using a preset calculation formula.

When the determination by the acceleration / stop command device 21 is an acceleration / stop command, the speed command generation unit 13 calculates a speed command for decreasing the acceleration based on the operation management information from the management control unit 12. The calculation of the speed command by the speed command generation unit 13 is performed every calculation cycle t _s .

  Thereafter, the power conversion device 8 is controlled by the movement control unit 14 in accordance with the calculated speed command, and the speed of the car 1 is controlled.

  Next, a method for estimating the regenerative voltage will be described. In the synchronous motor, the regenerative voltage increases as the rotational speed and torque increase. For this reason, the regenerative voltage becomes maximum between the end of constant speed travel (when the rotational speed is maximum) and the start of constant deceleration (when the deceleration torque is maximum). Also, in this section, due to the increase in deceleration, the rotational speed decreases and the deceleration torque increases, but the effect on the regenerative voltage is greater for the torque, so the regenerative voltage is maximized at the start of constant deceleration, The regenerative voltage at this time is estimated as the maximum value of the line voltage of the motor 4 on the deceleration side.

Here, it can be seen from the following d-axis and q-axis circuit equations that there are velocity electromotive forces that interfere with each other between the d-axis and the q-axis.

Non-interference control is performed in which the voltages of d and q are controlled as shown in the following equation to cancel them.

Therefore, the line voltage Va is obtained from the following equation.
V _a ² = V _da ² + V _qa ²
= (V _da '−w _re · L _a · I _qa ) ² + {V _qa ' + w _re (φ _fa + L _a · i _qa )} ²

Here, the electrical angular angular velocity w _re ′, the d-axis current I _d ′, and the q-axis current I _q ′ at time t ′ at which the constant deceleration at which the regenerative voltage starts to be maximum are estimated, respectively, using Equation (1). Get V _a '. Here, R _a is a resistance value, L _a is an inductance, and φ _fa is a maximum value of the number of armature winding interlinkage magnetic fluxes.
V _a ' ² = (R _a · I _d ' −L _a · I _q '· w _re ') ²
+ {R _a · I _q '+ w _re ' (φ _fa + L _a · I _d ')} ² (1)

The electrical angular velocity w _re ′ is estimated from the current speed v, acceleration A _a, and deceleration A _d during constant deceleration travel according to Equation (2). Here, t _a is the acceleration jerk time, t _d is the deceleration jerk time, D _s is the diameter of the drive sheave 5, and p is the number of poles of the motor 4.
_{w re '= {v + (} A a · t a -A d · t d) / 2} · (2 / D s) · p ··· (2)

When the regenerative voltage V _a ′ generated by the motor 4 reaches the limit value, the motor 4 rotates at a high speed, and a large d-axis current flows to cancel the counter electromotive force generated thereby. Here, assuming that the d-axis current flows to the limit value, the estimated value I _d ′ of the d-axis current at time t ′ is determined as shown in Expression (3). However, I _dmax is the maximum value of the d-axis current.
I _d '= I _dmax (3)

  The q-axis current is proportional to the torque generated by the motor 4, and the torque is roughly classified into an acceleration torque proportional to the acceleration, a load torque proportional to the load and the state of rope unbalance, and a loss torque inversely proportional to the speed. Therefore, the change in the three torque components from each time t during the constant acceleration to the constant deceleration start time t ′ is estimated and added to the torque at the time t to estimate the q-axis current.

The change ΔT _{acc in the} acceleration torque is obtained by the equation (4) from the acceleration A _a and the constant deceleration A _{d at} time t. However, the acceleration conversion coefficient K ₁ is expressed by the equation (5) using the gear ratio k and the moment of inertia G _D2 .
ΔT _acc = (A _a + A _d ) · K ₁ (4)
K ₁ = D _s · k · 19.6 / G _D2 (5)

The change ΔT _{1d in the} load torque is estimated from the change ΔRub in the rope unbalance, assuming that the load in the traveling car 1 is constant. First, constant acceleration A _a , constant deceleration A _d , constant acceleration time t ₁ , starting jerk time t _j , acceleration jerk time t _a , deceleration jerk time t _d , landing jerk time t _{L at} time t during constant acceleration. Is used to obtain a constant deceleration time t ₂ from equation (6).
t ₂ = (A _a / A _d ) {t ₁ + (t _j + t _a ) / 2} − (t _d + t _L ) / 2 (6)

From the constant acceleration / deceleration moving distance L _ad obtained by the speed command generator 13, the difference Rub ′ of the rope unbalance value between the time t and the time t ′ is calculated by the equation (7). However, the linear density of the rope system is ρ.
Rub ′ = L _ad · ρ (7)

From the rope unbalance values Rub and Rub ′ corresponding to the position of the car 1 at time t and time t ′, a change in rope unbalance is obtained, and this is set as a change ΔT _1d in the load torque as shown in equation (8). .
ΔT _1d = ΔRub = Rub′−Rub (8)

The change ΔT _loss in the _loss torque is inversely proportional to the speed difference between the time t and the time t ′, but since this speed difference is small, it is assumed that there is no change in the loss torque.
ΔT _loss = 0 (9)

Torque current I _q ′ during time t ′ is expressed by equation (10). However, the torque constant K _2, using the number p and the maximum value phi _fa of the armature winding flux linkage number of poles, represented by the formula (11).
I _q '= I _q + (ΔT _acc + ΔT _1d + ΔT _loss ) · K ₂ (10)
K ₂ = p · φ _fa (11)

  Next, a speed command from the speed command generator 13 when the motor 4 performs a regenerative operation will be described. FIG. 2 is a graph showing an example of a time change of the speed command value, acceleration, motor line voltage, regenerative voltage estimated value, and acceleration stop command in the elevator apparatus of FIG.

In FIG. 2, the dotted lines in the speed command value and acceleration graph are the speed / acceleration patterns calculated by the speed command generation unit 13 based on information from the management control unit 12 when the elevator is started. The vehicle travels along this pattern. However, the regenerative voltage becomes extremely high depending on the condition of the car load and the running condition, and the motor line voltage at the start of constant deceleration exceeds the voltage limit value V _dmax (dotted line in the line voltage graph).

To prevent this, the maximum value of the regenerative voltage is estimated during constant acceleration travel, and when this reaches the voltage limit value V _dmax , an acceleration stop command is output to the speed command generator 13. When receiving the acceleration stop command, the speed command generator 13 controls to stop the increase in the estimated regenerative voltage maximum value by decreasing the acceleration. Further, a new speed / acceleration pattern (speed command value and solid line of acceleration graph) is generated from the speed when acceleration is started to decrease, the remaining distance to the stop position, and is output to the movement control unit 14. .

  In such an elevator apparatus, the maximum speed is determined during constant acceleration in consideration that the regenerative voltage does not exceed the voltage limit value, so that regenerative power can be appropriately consumed. If the load on the other drive system equipment is within the allowable range, the speed of the car 1 can be increased at a constant acceleration until the regenerative voltage reaches the voltage limit value, so the car 1 can be operated with high efficiency. can do.

Claims (4)

A hoisting machine having a drive sheave and a motor for rotating the drive sheave;
Suspension means wound around the drive sheave,
A car suspended by the suspension means and raised and lowered by the hoisting machine;
A power converter that controls the power supplied to the motor; and a controller that controls the power converter;
The control device estimates the maximum value of the regenerative voltage during the regenerative operation of the hoist during travel of the car, and is estimated when the estimated maximum value of the regenerative voltage reaches a predetermined voltage limit value. The elevator apparatus which controls the said power converter device so that the increase in the maximum value of regenerative voltage may be stopped.   The elevator apparatus according to claim 1, wherein the control device stops an increase in the estimated maximum value of the regenerative voltage by decreasing the acceleration of the car. The motor is a synchronous motor driven by a d-axis current and a q-axis current,
The elevator apparatus according to claim 1, wherein the control apparatus estimates a maximum value of the regenerative voltage based on the d-axis current, the q-axis current, and the angular velocity of the motor.   The elevator apparatus according to claim 3, wherein the control device sets the d-axis current to a predetermined value and sets the q-axis current to a value determined based on at least an acceleration torque.

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